This Lodge Does not exist. Stop this enquiry.
It is whispered that within the halls of the Mistwalkers there exists an Assassins lodge known as the Black Blades, if you ask about them once, they don’t exist, ask about them twice and you won’t exist to ask a third time. Even members of the Mistwalkers won’t talk between themselves although there may be the odd nod between members. If they exist, the Black Blades business would be classified, if a member was to acknowledge their membership or discuss their operations, they wouldn’t be able to do it twice.
Such a secret organization, if it existed, would rarely take in new members, and anyone who openly asks about them or joining them would be instantly ruled out. Entrants into the Black Blades face difficult tasks and most that would, hypothetically, attempt to join would fail.
Such a lodge would teach specialist ways of killing and provide preferential treatment to those prospective members who use stealth and subterfuge to complete their tasks.
Members of this non-existant and purely hypothetical organisation might be expected to oppose and eliminate any illegal assassins they come across; the Brotherhood of Knives would be a particular enemy.
There are many wild rumours surrounding the Black Blades. It is said that they could be anyone in disguise, even your own family members, and that high-ranking members of other Guilds are in fact Black Blade sleeper agents ready to strike at those secretly disloyal to the Protectorate.
The black blades would have no official symbols, livery or titles, as they don’t exist. The leaders of such a shadowy organization would never be known, unless by a changing code name that only those in the know would ever recognise.
(Contact the character ref team if a career in the Black Blades interests you, then pray they don’t find you.)